TrigUpgradeTest: Fix working directory for tests
This fixes a bug introduced with !22218 (merged) making most TrigUpgradeTest ctests fail. It's not clear why the CI of the original MR did not flag this problem.
This fixes a bug introduced with !22218 (merged) making most TrigUpgradeTest ctests fail. It's not clear why the CI of the original MR did not flag this problem.